1. Field of the Invention
The present invention relates to a presensitized plastic card which can be used to prepare an identification (I.D.) card, a tamperproof I.D. card prepared therefrom, and a method of preparing said tamperproof identification card. More particularly, this invention relates to a tamperproof identification card of the type including a photographic image and other indicia for identifying the owner or holder of the card, a presensitized plastic card used to prepare the tamperproof I.D. card, and a process for preparing the tamperproof I.D. card in which a thermo-adhesive resin is incorporated in a photosensitive composition which is exposed and developed to reproduce the identification information.
2. Discussion of the Prior Art
The use of identity cards has become very wide spread in recent years, particularly in situations requiring identity control, such as passports, credit cards, banking cards, security employee cards, etc. In all of these cases it is desired to protect the identity card from tampering by unauthorized persons to protect the integrity of the card.
It is known, for example, to prepare cards of this type in which a thin film covered with a photograph of the owner or holder and certain identifying information, for example the name of the owner or holder, an identification number of other information, is glued to a polyvinyl chloride support. A film of transparent plastic material is glued to the surface in such a way that the whole is protected against damage. However, these identification cards are not entirely inviolable since the protective film can be easily unglued and the photograph can be changed or retouched.
One means for overcoming this disadvantage is to effect the photograph by the deposition of a photosensitive layer directly on the support, (see French Pat. No. 2,129,198). According to this patent, a support of polyvinyl chloride or other plastic material is covered with a photosensitive layer composed of a product sold under the trade name Dylux. According to the teachings in the French patent, the identifying information, e.g., alphanumeric inscriptions, and the photograph are reproduced on the photosensitive layer after the card is covered with its transparent protective film.
While providing some improvement these identification cards still suffer from several disadvantages due principally to the fact that the photosensitive emulsion is not temperature resistant. Since the lamination of the protective film to the support usually is affected by the application of heat, the photosensitive layer is susceptible to deterioration.
Moreover, the stabilization of the photograph, in the case of a simple exposure to light, is not uniform throughout the depth of the photograph. However, since the photosensitive material is protected by a transparent film it is no longer possible to stabilize the image after development by washing.
According to U.S. Pat. No. 3,002,851, an identification card is prepared by coating a support of polyvinyl chloride with a photosensitive diazo solution such as condensed paradiazodiphenylamine formaldehyde, to which a sufficiently high pressure is exerted at an elevated temperature so that the photosensitive layer will pass partially into the support. However, it has been found that the adherence of the layer to the support is still insufficient. Therefore, if a protective film customarily used for identification cards is laminated to the coated support, there is observed only a weak adherence of the protective film and, in addition, the information tends to transfer to the protective film in the course of the delamination of the latter.
In addition, the photosensitive layer tends to be easily attacked by solvents, such as acetone.
It has recently been proposed in U.S. Pat. No. 4,115,618 to provide an identification card which provides a "security seal" between the photograph and the surface of the protective plastic material bonded thereto. This patent provides as the protective film a plastomeric sheet material comprising a cellulose ester sheet, one surface of which is hydrolyzed and bonded to the hydrolyzed surface, a layer consisting essentially of a mixture of hydrolyzed polyvinyl alcohol and a low molecular weight polyvinyl acetate. These identification cards use Polaroid diffusion transfer color images which are of the silver type.
This system also has several difficulties and drawbacks due principally to the use of silver type photographs. These photographs are expensive and requires a delicate process for their use. For example, it is necessary to apply the protective film immediately after the development of the film while the photograph is still wet. Furthermore, the security seal does not render this card tamperproof since it is still possible to completely tear off the protective film and the photograph and to replace them with a new photograph and a new protective film. In addition, these identification cards present significant thicknesses on the order of several tenths of millimeters to accomodate the photographs.
Accordingly, there has not yet been a single identification card which is substantially inviolable and tamperproof and which offers a total adherence between the support and the photograph or other information as well as between the photograph and the protective film, without significant thickness and, at the same time, which is simple to produce and inexpensive.
These disadvantages are now remedied by the tamperproof identification cards of the present invention. Accordingly, a principal object of the present invention is to provide tamperproof identification cards which are simple and inexpensive to produce and use readily available materials.
It is a further object of this invention to provide a tamperproof identification card which includes a photograph of the owner or holder and which provide adherence between the support and the photograph as well as between the photograph and the protective film.
A further object of the present invention is to provide a presensitized plastic card from which the tamperproof identification cards of the subject invention can be produced.
A still further object of the present invention is to provide a process for preparing the tamperproof identification cards.
These and other objects of the present invention will become more apparent from the following description and accompanying drawings in which: